This application requests support for a FASEB Summer Conference entitled Gastrointestinal Tract XV: Epithelia, Microbes, Inflammation and Cancer (Drs. Asma Nusrat, Robert Coffey, and Thaddeus Stappenbeck, co-chairs). The 5 day conference will be the 15th in a series of biennial meetings that over the last 28 years has provided an intense and intimate venue for presentation, discussion, and exchange of ideas among scientists at the forefront of research in fields related to gastrointestinal health and disease. The rapid scientific advances in development, epithelial/stem cell biology, mucosal immunology, microbiology and physiology of the gastrointestinal (GI) tract dictate the need to continue this series of conferences, which was agreed upon by the unanimous vote of attendees at the last meeting, held August 14-18, 2011, at Steamboat Springs, Colorado. We anticipate the attendance of ~ 160 scientists and trainees at the 2013 meeting that will be held at Steamboat Springs, Colorado from August 11-15, 2013. Many of the topics are highly relevant to the goals of the NIDDK mission including gastrointestinal cancer stem cells, host-pathogen interactions, microbial ecology, mucosal immunity, inflammation and epithelial properties/repair. We have developed a format that is designed to facilitate translation of basic biology into new medically relevant approaches to human disease. The Steamboat Conference Center is a well-established site for FASEB conferences and is fully equipped and well suited to support this meeting. Forty-one speakers and session chairs have been confirmed for this meeting. In addition, two poster sessions are planned, thirteen abstracts will be selected for oral presentation and an afternoon will be devoted to a Meet the Experts and an NIH workshops.